This invention relates to formwork for casting vertical concrete structures such as walls, wherein forms or elongated modular elements are adapted to interconnect to one another along their longitudinal sides to create overall formwork.
It is known in the prior art to provide modular form elements which interconnect to form a wall structure into which concrete may be poured or into which insulation may be inserted. An example of such elements is disclosed in PCT application PCT/CA 95/00281 by Piccone. The structure disclosed in PCT/CA95/00281 comprises a plurality of elongated and generally concave elements which are placed edge to edge to form parallel faces of a wall. The two faces of the wall are connected by connecting members extending between the two wall faces. The connecting members are in sliding engagement with the concave elements. The connecting members also serve to simultaneously connect adjacent concave elements of each wall to one another.
The structure and modular elements described in PCT/CA 95/00281 result in a wall having a uniform columnar appearance. However, it is sometimes desired to construct a wall having one or both of its sides flat.
It is therefore an object of this invention to provide improved modular formwork elements for use in a formwork assembly which provide versatility in the shape of the wall to be constructed, including the ability to form a wall having at least one flat side.
It is a further object of the invention to prevent bulging of the formwork under the pressure of poured concrete against a flat wall face and to provide improved strength for the overall formwork.
The invention comprises a kit, an assembly and individual elements for formwork for erecting a wall structure wherein a plurality of elongated wall elements having engagement means about their longitudinal edges are presented in edge to edge relationship in two spaced parallel rows and a connecting member having engagement means slidingly extends between the parallel rows so as to simultaneously engage two edge adjacent wall elements in one row and two edge adjacent wall elements in the parallel row, the elongated wall elements which define at least one of said parallel rows being substantially flat on one side.
According to the invention, a formwork element is provided which is elongated and has a flat central portion extending between two longitudinal edges. One of the longitudinal edges is provided with engagement means extending at substantially a 45 degree angle with respect to said central portion and the other of said longitudinal edges is provided with engagement means extending at substantially a 135 degree angle in relation to said central portion. The engagement means of the formwork element are adapted to slidingly engage said engagement means of said substantially flat wall elements and said engagement means of said connecting member.
In another aspect of the invention, rigid panels extend substantially between adjacent pairs of connecting members and against an interior surface of a flat wall formed by flat wall elements disposed in edge to edge relationship.
In another aspect of the invention, the connecting member is elongated and comprises a substantially straight portion extending between two longitudinal edges. Each of longitudinal edge is provided with two elongated engagement means disposed in symmetrical opposed relationship about the plane of the straight portion, each of said engagement means of said connecting member being adapted for sliding engagement with the engagement means of the wall elements.
In another aspect of the invention, the connecting member further comprises at least one elongated supplementary engagement means spaced inwardly from one of said longitudinal edges.
In another aspect of the invention, a flat wall defining element is elongated and comprises a portion extending between two longitudinal edges which portion is flat on one of its surfaces. Each longitudinal edge is provided with elongated engagement means adapted for sliding engagement with the engagement means of said connecting member.
Other aspects of the invention are described in the description of the preferred and alternate embodiments below and in the claims.